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/**********************************************
License: BSD
Project Webpage: http://cajun-jsonapi.sourceforge.net/
Author: Terry Caton
***********************************************/
#pragma once
#include "elements.h"
#include <iostream>
#include <vector>
namespace json
{
class Reader
{
public:
// this structure will be reported in one of the exceptions defined below
struct Location
{
Location();
unsigned int m_nLine; // document line, zero-indexed
unsigned int m_nLineOffset; // character offset from beginning of line, zero indexed
unsigned int m_nDocOffset; // character offset from entire document, zero indexed
};
// thrown during the first phase of reading. generally catches low-level problems such
// as errant characters or corrupt/incomplete documents
class ScanException : public Exception
{
public:
ScanException(const std::string& sMessage, const Reader::Location& locError) :
Exception(sMessage),
m_locError(locError) {}
Reader::Location m_locError;
};
// thrown during the second phase of reading. generally catches higher-level problems such
// as missing commas or brackets
class ParseException : public Exception
{
public:
ParseException(const std::string& sMessage, const Reader::Location& locTokenBegin, const Reader::Location& locTokenEnd) :
Exception(sMessage),
m_locTokenBegin(locTokenBegin),
m_locTokenEnd(locTokenEnd) {}
Reader::Location m_locTokenBegin;
Reader::Location m_locTokenEnd;
};
// if you know what the document looks like, call one of these...
static void Read(Object& object, std::istream& istr);
static void Read(Array& array, std::istream& istr);
static void Read(String& string, std::istream& istr);
static void Read(Number& number, std::istream& istr);
static void Read(Boolean& boolean, std::istream& istr);
static void Read(Null& null, std::istream& istr);
// ...otherwise, if you don't know, call this & visit it
static void Read(UnknownElement& elementRoot, std::istream& istr);
private:
struct Token
{
enum Type
{
TOKEN_OBJECT_BEGIN, // {
TOKEN_OBJECT_END, // }
TOKEN_ARRAY_BEGIN, // [
TOKEN_ARRAY_END, // ]
TOKEN_NEXT_ELEMENT, // ,
TOKEN_MEMBER_ASSIGN, // :
TOKEN_STRING, // "xxx"
TOKEN_NUMBER, // [+/-]000.000[e[+/-]000]
TOKEN_BOOLEAN, // true -or- false
TOKEN_NULL // null
};
Type nType;
std::string sValue;
// for malformed file debugging
Reader::Location locBegin;
Reader::Location locEnd;
};
class InputStream;
class TokenStream;
typedef std::vector<Token> Tokens;
template <typename ElementTypeT>
static void Read_i(ElementTypeT& element, std::istream& istr);
// scanning istream into token sequence
void Scan(Tokens& tokens, InputStream& inputStream);
void EatWhiteSpace(InputStream& inputStream);
void MatchString(std::string& sValue, InputStream& inputStream);
void MatchNumber(std::string& sNumber, InputStream& inputStream);
void MatchExpectedString(const std::string& sExpected, InputStream& inputStream);
// parsing token sequence into element structure
void Parse(UnknownElement& element, TokenStream& tokenStream);
void Parse(Object& object, TokenStream& tokenStream);
void Parse(Array& array, TokenStream& tokenStream);
void Parse(String& string, TokenStream& tokenStream);
void Parse(Number& number, TokenStream& tokenStream);
void Parse(Boolean& boolean, TokenStream& tokenStream);
void Parse(Null& null, TokenStream& tokenStream);
const std::string& MatchExpectedToken(Token::Type nExpected, TokenStream& tokenStream);
};
} // End namespace
#include "reader.inl"
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